1. Field of the Invention
The present invention relates to a method for manufacturing a translucent (light-transmitting) rigid substrate laminate, and particularly to a method for manufacturing a plate glass laminate for manufacturing a protection glass of a display element.
2. Description of the Related Art
Display elements such as liquid crystal displays (LCDs), organic EL displays (OELDs), electroluminescent displays (ELDs), field emission displays (FEDs), plasma displays (PDPs) and the like are used in display devices of various kinds of electronic equipment such as televisions, laptop computers, car navigation systems, electronic calculators, mobile phones, electronic schedulers and personal digital assistants (PDAs). Further, a plate glass product for protection is generally installed to face the display element in order to protect the display element. Recently, a conductive film having a predetermined pattern on the surface of the plate glass product for protection is often provided so that it serves as a touch panel.
In the plate glass product, the glass plate is processed in a size and shape that are appropriate for each display device. In order to satisfy a cost level required in the market, it is required that a large amount of plate glass products are processed with high production efficiency.
Accordingly, Japanese Patent Application Laid-Open (JP-A) No. 2009-256125 (Patent Literature 1) proposes a method for increasing production efficiency for a plate glass product. Specifically, the proposed is “a method for processing a plate glass, including: forming a material glass block (A) obtained by laminating a plurality of material plate glasses 1, and at the same time, integrally fixing each material plate glass 1 by a strippable fixing agent 2 interposed between the material plate glasses 1; forming a division glass block (B) having a small area by dividing the material glass block (A) in a surface direction; forming a product glass block (C) in a product form when viewed in a plan view by processing at least an outer boundary of the division glass block (B); and individually separating the product glass block (C) after an edge face of the product glass block (C) is processed” (claim 1). Accordingly, there is described that “since division, external shape processing and edge face processing are performed after a plurality of material plate glasses are laminated, a plurality of plate glass products may be obtained by a fewer processes and productivity is increased” (Paragraph 0007).
Further, Patent Literature 1 describes that “the fixing agent 2 interposed between the material plate glasses 1 is a photo-curable liquid fixing agent that is cured when UV is irradiated and then softened when a temperature is increased (claim 4). Accordingly, there is described that “if pressure is applied in upper and lower directions by interposing the photo-curable liquid fixing agent between the upper and lower material plate glasses, the liquid fixing agent spreads to have a constant thickness in a film form on the entire surface between the upper and lower material plate glasses, and if infrared rays are irradiated in this state, the liquid fixing agent spreading in the film form is cured to integrally fix the upper and lower plate glasses. Therefore, a plurality of material plate glasses may be rapidly laminated with high precision so as to be integrally fixed. In addition, after final processing (edge face processing), if the product glass block is accommodated in warm water and the like to increase the temperature, the fixing agent cured between the plate glasses is softened and separated in a film form. Therefore, it is easy to recover and treat the fixing agent without causing environmental pollution” (Paragraph 0007).
The paragraphs of “Best Mode for Carrying Out the Invention” of Patent Literature 1 describes that twenty material plate glasses are laminated while the photo-curable liquid fixing agent is interposed between the material plate glasses, subsequently, the fixing agent is cured by irradiating UV rays (UV light) to the upper surface of the laminated material plate glasses, and the material glass block where the upper and lower material plate glasses are integrally fixed is formed (paragraphs 0010 to 0011).
Meanwhile, as a method for bonding a plate glass with high precision, a method using a roller is known. For example, JP-A No. 2009-40617 (Patent Literature 2) describes a method for bonding a plate glass, including: bonding a base glass (G) on an object to be bonded (F) by applying pressure while an adsorbent is retracted from an adhesion position into a retraction position before an adhesion movement of an adhesion roller in the process of moving the adhesion roller from an adhesion start edge toward an adhesion end edge. Patent Literature 2 describes that the base glass G and the object to be bonded F may be always bonded properly while air is securely prevented from being interposed between the bonding faces of the both.
Further, Patent Literature 2 also describes that: the misalignment of the object to be bonded (F) and the base glass (G) is optically detected by a misalignment detection device, and the objected to be bonded (F) and the base glass (G) are positioned by a position adjustment device; an adhesive layer covered with a release paper is formed on one face of the object to be bonded, and the release paper is delaminated during the bonding; the adhesive layer may be formed of an UV curing resin, and in that case, it is preferable that G and F are bonded by a bonding apparatus described in Patent Literature 2, and then the adhesive layer is subjected to curing treatment; and the like.